Project Abstract Today over 60 million Americans have prediabetes, and it is estimated that almost one quarter of these individuals could develop diabetes within the next 5 to 7 years. The Diabetes Prevention Program (DPP) demonstrated that an intensive lifestyle intervention resulting in modest weight loss and increased physical activity can delay or prevent the development of type 2 diabetes for adults with prediabetes. Unfortunately, the DPP lifestyle intervention was not initially designed for delivery on a public health scale, and the costs and intensity of this intervention have delayed any passive dissemination of this approach since the DPP's results were first released some 9 years ago. However, recent studies by our group at Indiana University have demonstrated that delivery of a group-based adaptation of the DPP lifestyle intervention by trained YMCA employees can achieve weight loss and behavioral changes similar to the DPP but for only about 1/8 the cost. Now, through a new partnership involving UnitedHealth Group (UHG) and the YMCA of USA, efforts are actively underway to scale this model for DPP delivery nationally. In this exciting collaboration, UHG will provide a new administrative service for employer groups and other health purchasers that will help to identify adults with pre-diabetes, reach out to these high risk persons, and assist them in enrolling in the YMCA's group-based DPP intervention program. UHG will then manage a system of value-driven payments to the YMCA, based on levels of participation and weight loss achieved by each high risk person who is enrolled. Although this will not suffice as the only means for addressing the prevention and control of diabetes on a population scale, this new partnership creates an exciting opportunity to evaluate the feasibility and sustainability of a generalizable way for delivering the DPP nationally through efforts that involve a large commercial health payer and a leading community organization. With the strong support of both UnitedHealth Group and the YMCA to provide extensive and ongoing access to several administrative data sources, we propose to evaluate the reach, implementation, costs, effectiveness, and maintenance of these efforts for tens of thousands of high risk adults in multiple regions throughout the U.S. Through a national survey of large employers, we will also collect information regarding incentives and payment for weight management and chronic disease prevention services. Through these efforts, we hope to understand more about the factors that impact reach and effectiveness of this new program as the structure of payment varies across different UHG markets, and we also hope to identify how changes in the delivery model or benefit structure over time might help to enhance reach to more employer groups and to improve participation and weight loss success for more individuals. Should our evaluation find this partnered prevention strategy to be cost- effective and sustainable, these results will be pivotal to the timely dissemination of an important new component of nationwide efforts to prevent type 2 diabetes among over 60 million Americans who already have prediabetes today.